Si_3N_4/BN_(f)复合材料的相界面

Interfaces in Si_3N_4/BN_(f) Composite

本文借助高分辨电子显微镜研究了Si3N4／BN（f）复合材料的相界面,研究发现，BN纤维的两端与基体结合牢固，界面不易解离，材料断裂过程中纤维很难拔出．材料的韧性主要通过BN纤维自身（001）面上的滑移、撕裂和弯曲以及BN纤维的侧表面与Si3N4颗粒的界面上的解离等途径得以提高．

Interfaces in St3N4 /BN(f) composite were studied by using high resolution electron microscope (HREM). It was revealed that fibers ends, botll tops and bases, were closely bonded with the matrix grains. Fiber pull-out had hardly any contribution to the improvement in fracture toughness of the composite material. HREM observations suggested that the increased fracture energy absorbed came mainly from sliding, tearing and curving Oil (001) plane of BN fibers and debonding at the interfaces between St3N4 and side surfaces of BN fibers.